Fire-extinguishing device with a fire-extinguishing fluid

ABSTRACT

A fire extinguishing device activates fire extinguishing nozzle-heads in multiple locations in response to fire-induced activation of one of the fire extinguishing nozzle-heads. The fire extinguishing nozzle-heads are connected to a supply pipe which conducts a fire extinguishing fluid from a pressure generator. Each nozzle-head includes at least one fire extinguishing nozzle and a fire detection contrivance, which, in the event of a fire, triggers the issue of the extinguishing fluid from the activated fire extinguishing nozzle. Each of the fire extinguishing nozzles-heads further includes at least two connecting channels providing communication between the fire extinguishing nozzles and a supply pipe. Both connecting channels are normally closed by respective shut-off devices while the extinguishing nozzle-heads are in a quiescent state. In the event of a fire, the heat generated thereby triggers the fire detection contrivance, which in turn opens a connecting channel by responsive operation of a corresponding one of the shut-off devices. In response to the attendant pressure drop, a signal is sent to the pressure generator which increases the pressure in the supply pipe. The other shut-off device is designed to open when a minimum pressure in the supply pipe is exceeded, and thereby activates the remaining fire extinguishing nozzle-heads not already directly activated in response to fire-related heat.

The present invention relates to a device for extinguishing fires bymeans of an extinguishing fluid comprising a supply pipe conducting theextinguishing fluid; the said supply pipe connecting a pump with aplural number of fire extinguishing nozzle-heads, each comprising atleast one fire extinguishing nozzle; this nozzle being connected to thesupply pipe by way of at least one connecting channel; and comprising afire detection contrivance which, in the case of a fire, triggers theissue of extinguishing fluid from the fire extinguishing nozzles. Inthis at least with one of the fire extinguishing nozzle heads, the issueof extinguishing fluid from at least one of the extinguishing nozzles isclosed off by a shut-off device which opens automatically when theminimum pressure of the extinguishing fluid is exceeded. Such fireextinguishing devices are stationary installations in buildings orships. In addition, the invention relates to a fire extinguishingnozzle-head for a device of the type mentioned above for extinguishingfires.

Known devices are usually equipped with a pressure generator, forexample a pump, for generating the extinguishing fluid pressure requiredfor firefighting and with fire extinguishing nozzles arranged in thelocalities susceptible to fires; the said fire extinguishing nozzles areconnected to the pressure generator by way of a system of supply pipes.In the case of a fire, the issue of extinguishing fluid from the fireextinguishing nozzles is triggered by a fire detection contrivance whichis allocated to each of the fire extinguishing nozzles.

One problem when operating extinguishing devices of the type describedabove is that if a fire breaks out only in a limited area of a sector oran enclosed space, in each instance only the fire extinguishing nozzlesallocated to the respective area are opened. This in turn leads to thedanger that insufficient extinguishing fluid is supplied to thesurroundings of the seat of the fire, so that the fire also encroachesupon the remaining areas of the sector, in spite of the fireextinguishing nozzles allocated to the seat of the fire being opened. Inthe case of a fire breaking out within a sector, it is thus necessary toopen not only the fire extinguishing nozzles directly allocated to theseat of the fire, but all fire extinguishing nozzles installed in thesector. In order to meet these requirements, as a rule, complicated andexpensive fire detection contrivances or control systems are used.

An extinguishing nozzle-head of the type described above is known frompublication of the PCT application WO-A-94/16771. In the known fireextinguishing nozzle-head, the connecting channel by which the fireextinguishing nozzle is connected to the supply pipe, in the quiescentstate is closed by a piston. This piston is supported by way of ahelical spring on a glass vial as is normally used as a fire detectioncontrivance with these types of fire extinguishing nozzle-heads. Thequiescent-state pressure of the extinguishing fluid present in thesupply pipe impinges on the piston.

In the known fire extinguishing nozzle-head, the length of the spring isdesigned in such a way that in the case of a fire, the travel thatbecomes free as a result of the fire detector shattering, is sufficientto move the piston into its open position, with the spring beinguntensioned. At the same time, the force of the spring is such that inthe case of an increase in the pressure in the supply pipe, the springis compressed and the piston is moved in this way into its openposition.

The known fire extinguishing nozzle-head allows significantsimplification in the design and control of fire extinguishing deviceswhere a plural number of fire extinguishing nozzle-heads must be openeddepending on the location of the fire. Due to the close tolerance limitswithin which the spring and the piston must be designed and moved, theknown fire extinguishing nozzle-head has been found to be prone tomalfunction.

It is the object of the present invention, by simple and economic meansto improve the reliability of a device for extinguishing fires, of thetype mentioned in the introduction, and of a fire extinguishingnozzle-head used in such a device.

According to the invention, this object is met in regard to the devicefor extinguishing fires in that each of the fire extinguishing nozzlesof the fire extinguishing nozzle-head is connected to the supply pipe byway of at least two connecting channels, with one of the connectingchannels in its quiescent state being shut off by a first shut-offdevice which opens up if the minimum pressure of the extinguishing fluidis exceeded, and the other of the connecting channels in its quiescentstate being shut off by a second shut-off device which in the case of afire can be opened by the fire detection contrivance.

In regard to the fire extinguishing nozzle-head, this object is met inthat the fire extinguishing nozzle, of which there is at least one, ofthe fire extinguishing nozzle-head is connected to the supply pipe byway of at least two connecting channels, with one of the connectingchannels in its quiescent state being shut off by a first shut-offdevice which opens up if the minimum pressure of the extinguishing fluidis exceeded, and the other of the connecting channels in its quiescentstate being shut off by a second shut-off device which is coupled to thefire detection contrivance in such a way that, in the case of a fire,the fire detection contrivance causes the second shut-off device toopen.

According to the invention it is provided that, corresponding to theexisting art known from the above-mentioned PCT application, the issueof extinguishing fluid from the fire extinguishing nozzle-head can beeffected alone by switching on the pressure generator connected to thefire extinguishing nozzle-head, for example following a respectivesignal from the fire detection contrivance. After switching on the pump,the pressure within the supply pipe system increases. When a certainlimit pressure is exceeded, the shut-off device activated by exceedingthe minimum pressure automatically opens.

Since with the fire extinguishing device according to the invention, twoconnecting channels for connecting the fire extinguishing nozzle of thefire extinguishing nozzle-head designed accordingly, to the supplychannel, are provided, two shut-off devices operating totally separatelyfrom each other without influencing each other, can be used. It is thuspossible without any problem to optimally adapt each of these shut-offdevices to its respective requirement. In this way it is assured that inthe case of a fire, devices according to the invention, and inparticular the fire extinguishing nozzle-heads designed according to theinvention used in them, provide a high degree of operational safety andreliability.

The opening of the shut-off device, in the case of a fire, by the firedetection contrivance which is connected to the said fire detectioncontrivance and the resulting issue of extinguishing fluid from the fireextinguishing nozzle, causes a drop in pressure in the supply pipe. Thisdrop in pressure can be detected by a control and monitoring systemallocated to the pressure generator; the said control and monitoringsystem then activates the pressure generator. Alternatively, it is alsopossible to evaluate the increase in flow speed in the supply pipe as asignal for switching the pressure generator on. Switching on thepressure generator results in an increase in the pressure of the fluidto the point where the minimum pressure is exceeded. This exceeding ofthe minimum pressure causes an opening of the shut-off devices withother fire extinguishing nozzle-heads, designed according to theinvention, which are also connected to the supply pipe, whichautomatically open when a minimum pressure is exceeded. By means of fireextinguishing nozzle-heads designed according to the invention, anextinguishing device can be constructed which is safe and activated onlyby triggering a single fire extinguishing nozzle-head of the firedetection contrivance.

Since in the case of extinguishing devices equipped with fireextinguishing nozzle-heads designed according to the invention neitheradditional supply pipes nor expensive fire detection or control systemsare needed in order to ensure, in the case of a fire, opening of all thefire extinguishing nozzles meeting the above-mentioned requirements,such a device can be set up economically. In particular it is alsopossible to convert existing systems by retrofitting them with fireextinguishing nozzle-heads designed according to the invention.

As is the case with existing art, the fire detection contrivance shouldalso preferably be an element, destroyable by the effect of heat, onwhich a movable valve piston is spring-supported; this spring-supportedvalve piston comprising a shut-off device openable by the fire detectioncontrivance. In this way the fire detection contrivance and therespective shut-off device can be realised easily using very littlespace. This is the case in particular if the element, destroyable by theeffect of heat, is a glass vial.

The fire extinguishing nozzle-head according to the invention can beused in a particularly advantageous way if the fire extinguishingnozzles create an extinguishing mist from the extinguishing fluid. Whenusing an extinguishing mist made from an extinguishing fluid, a fire canbe extinguished with a minimum of extinguishing fluid.

With a fire extinguishing head according to the invention, the costs canbe kept particularly low, while at the same time operational safety androbustness are kept high, in that the shut-off device openable by anincrease in pressure of the extinguishing fluid comprises a burstingdisk. By respective selection of the materials and by suitabledimensioning, such bursting disks can easily be adapted to therespective operating conditions.

Alternatively or in addition, the shut-off device, opening as a resultof an increase in pressure of the extinguishing fluid, can be designedas a movable valve body loaded by elastic restoring force, which valvebody comprises at least a first pressure surface upon which the fluidexerts pressure essentially directed against the restoring force. Thisembodiment of the invention can be used with particular advantage inthose cases where the connecting channel leads to a chamber surroundingthe first pressure surface and where a connecting channel leading to thechamber can be shut off by way of a section of the first pressuresurface. Alternatively or in addition, by a single movement of the valvebody, it should be possible to open at least one of the connectingchannels, and it should be possible to shut off at least one furtherconnecting channel. In both cases it is possible, depending on thepressure present in the supply pipe, to control the issue ofextinguishing fluid from various nozzles. This is particularlyadvantageous if the device according to the invention is used forfirefighting with extinguishing fluid mist, because in this case thecomposition of the extinguishing mist can be controlled in a simplemanner.

Below, the invention is illustrated in more detail by means of a drawingrepresenting two embodiments, as follows:

FIG. 1 shows a first fire extinguishing nozzle-head in axiallongitudinal section;

FIG. 2 shows a second fire extinguishing nozzle-head in axiallongitudinal section.

The fire extinguishing nozzle-head shown in FIG. 1 comprises a conicallybevelled circumferential area 2 into which retainers 3 for fireextinguishing nozzles (not shown) are shaped. For this purpose, theretainers 3 comprise internal screw threads 4 into which the fireextinguishing nozzles can be screwed by means of respective externalthreads on the said fire extinguishing nozzles. Apart from the retainers3 for the fire extinguishing nozzles (not shown), the fire extinguishingnozzle-head 1 comprises a central bore hole 5 in which an axiallymovable valve piston 6 is arranged. In the area of the face 7 of thefire extinguishing nozzle-head 1, the bore hole 5 comprises a section 8with a larger diameter when compared to the remaining sections of thebore hole 5, with an internal screw thread 9 formed in its wall. Theprotective cap 10 of a fire detection contrivance 11 is screwed into theinternal screw thread 9.

The protective cap 10 of the fire detection contrivance 11 protrudesfreely into the space from the face 7 of the fire extinguishingnozzle-head. A piston-shaped glass vial 13 is inserted into the internalrecess 12 of the protective cap 11; at the end 14 of the said glass vialallocated to the fire extinguishing nozzle-head 1, the valve piston 6 issupported.

The valve piston 6 comprises an axial blind hole 15, emanating from therear face, allocated to the bottom 14 of the bore hole 5, of the saidvalve piston. Through-bore holes 16, arranged in radial direction to thecircumferential area of the valve piston 6, in the middle area of thevalve piston 5, lead into the said blind hole 15. The through-bore holes16 connect the blind hole 15 of the valve piston 6 with an annularchamber 17 shaped into the bore hole 5. The retainer 3 for the fireextinguishing nozzles (not shown) are shaped into the said annularchamber.

In addition, the valve piston 6 in its rear area comprises a section 18with a diameter reduced to such an extent that a clear space 19 iscreated in the central bore hole 5 of the fire extinguishingnozzle-head 1. A connecting channel 20 leads into this clear space 19. Aconnection 21, shaped at the rear of the fire extinguishing nozzle-head,for a supply pipe 27, is connected with the central bore hole 5 of thefire extinguishing nozzle-head 1 by way of the connecting channel 20. Inthe quiescent state, as shown in FIG. 1, of the fire extinguishingnozzle-head 1, the clear space 19 of the central bore hole 5 is sealedtowards the annular chamber 17 by an annular seal 22 borne by the valvepiston 6.

The blind hole 15 of the valve piston 6 is sealed, by a bursting disk23, against a rearward clear space 24 of the central bore hole 5 of thefire extinguishing nozzle-head 1 which is provided between the burstingdisk 23 and the bottom 14 of the central bore hole 5. Seated in theclear space 24 there is a helical spring 26 which in the quiescent stateof the fire extinguishing nozzle-head 1 exerts a spring force, directedtowards the glass vial 13, on the valve piston 6. In addition a secondconnecting channel 25 which connects the clear space 24 of the centralbore hole 5 with the connection 21 for the supply pipe 27 leads to theclear space 24.

The fire extinguishing nozzle-head 51 shown in FIG. 2 comprisesretainers 53, shaped into its conically bevelled circumferential area52; extinguishing nozzles (not shown) can be screwed into the saidretainers. As is the case with fire extinguishing nozzle-head 1 of FIG.1, the fire extinguishing nozzle-head 51 comprises a central bore hole54 in which a piston 55 is arranged in an axially movable manner. Thepiston 55 is shaped in the same way as the piston 6 shown in FIG. 1.Accordingly, a clear space 56 is created by a section with a reduceddiameter arranged at the rear of the piston 55. A first connectingchannel 57 leads into this clear space. The other end of the connectingchannel 57 is connected to a connection 58 for a supply pipe 77.

A clear space 60 is provided between the rear end of the piston 55 andthe bottom 59 of the bore hole 54. A helical spring 76, which exertspressure on the piston 55 in the direction of the tip 61 of the saidpiston 55, is arranged in the clear space 60.

The clear space 56 is sealed against the remaining sections of thecentral bore hole 54 by means of annular seals 62, 63 inserted intogrooves which are provided in the rearward end section 64 or the middlesection 65 of the piston 55.

The tip 61 of the piston 55 is resting against a glass vial 66 seated inthe recess 67 of a protective cap 68. As is the case with cap 11 shownin FIG. 1, the protective cap 68 is screwed into the diameter-enlargedfrontal section 69 of the central bore hole 54.

The retainers 53 for the fire extinguishing nozzles (not shown) areconnected to the cental bore holes 54 by connecting channels (not shown)in such a way that in the quiescent state as shown in FIG. 2, theconnecting channel 57 is sealed off against the retainers 53.

The connection 58 for the supply pipe 77 is connected to a furtherretainer 71 by way of a second connecting channel 70. A furtherconnecting channel 73 is shaped into the bottom 72 of the retainer 71;the said connecting channel connects the retainer 71 to the retainers 53for the extinguishing nozzles (not shown). A bursting disk 74 can beinserted into the retainer 71 in such a way that the bursting disk 74rests against the bottom 72 of the retainer 71 and seals off theconnecting channel 73. The retainer 71 is closed off by a plug 75 whichcan be screwed into the retainer 71; at the same time the plug 75ensures that the bursting disk 74 is held to the bottom 72 of theretainer 71.

The device, described here, according to the invention, forextinguishing fires by means of an extinguishing fluid, comprises aplural number of fire extinguishing nozzle-heads 1 or 51 which arearranged, spaced apart from each other, in an area susceptible to fires.The fire extinguishing nozzle-heads 1 or 51 are connected, by way ofsupply pipes 27 or 77, to a pressure generator 28 or 78, for example apump or a pressure cylinder. In this, the pressure of the extinguishingfluid within the supply pipe system is controlled by a surveillance andcontrol system (not shown). In the quiescent state of the device, thepressure in the supply pipe system is relatively low at for example 5 to8 bar.

If a fire does occur, a device equipped with the fire extinguishingnozzle-heads 1 shown in FIG. 1 works as follows:

Due to the effect of the heat generated when a fire occurs, the glassvial 13 of the fire extinguishing nozzle-head 1 in closest proximity tothe place where the fire is occurring, is destroyed. Subsequently, as aresult of the spring force of the spring 26, the piston 6 is moved inthe direction of the front 7 of the fire extinguishing nozzle-head 1. Asa result of this movement, the first connecting channel 20 is connectedto the retainers 3 by way of the clear space 19 and the annular chamber17, so that extinguishing fluid emanates from the fire extinguishingnozzles screwed into the retainers 3.

The drop in pressure in the supply pipe system, associated with theissue of extinguishing fluid, is detected by the monitoring and controlsystem (not shown). Subsequently the said monitoring and control systemtransmits a control signal to the pressure generator 28 whichsubsequently increases the pressure of the extinguishing fluid withinthe supply pipe system again. As soon as the pressure within the supplypipe system reaches a defined limit value, for example 40 bar, thebursting disks 23 burst on those fire extinguishing nozzle-heads wherethe glass vials 14 had not been destroyed when the fire started.Subsequently, extinguishing fluid reaches the retainer 3 by way of thesecond connecting channel 25, the blind bore hole 15, the through-borehole 16 and the annular chamber 17; the extinguishing fluid thenemanates from the fire extinguishing nozzles (not shown). From thismoment onwards, all the fire extinguishing nozzles contribute to thefirefighting effort and safely prevent any spreading of the fire toareas adjacent to the fire. In this, due to the short time required forincreasing the pressure within the supply pipe system, the time lapsebetween the destruction of the glass vial 13 of the fire extinguishingnozzle-heads 1 in closest proximity to the fire, and the bursting of thebursting disks 13 of the other respective fire extinguishingnozzle-heads 1, is short enough to meet the legal requirements.

In principle, a device equipped with fire extinguishing nozzle-heads 51of the type described here, functions in the same manner as the devicementioned above, equipped with fire extinguishing nozzle-heads 1. Withthe fire extinguishing nozzle-heads 51, too, during destruction of theglass vial 66 the first connecting channel 57 is connected as a resultof the movement of the piston 55 associated with the destruction of theglass vial 66, with the retainers 53, by way of the clear space 56 andthe annular channel (not shown), From this moment onwards, extinguishingfluid emanates from the fire extinguishing nozzles (not shown) screwedinto the recesses 53.

With those fire extinguishing nozzle-heads 51 where the effect of theheat associated with the start of the fire did not destroy the glassvials 66, the bursting disk 74 bursts as soon as the pressure within thesupply pipe system, by way of the pressure generator (not 78) activatedby the control and monitoring system, has exceeded a particular limitvalue. Once the fire has been extinguished, it is particularly easy toreplace the bursting disk 74 that may have been destroyed, by unscrewingthe plug 75.

The above explanations always refer to devices which may be equippedwith any fire extinguishing nozzles. However, the device according tothe invention is particularly suitable for those fire extinguishingnozzles which generate a fluid mist from the extinguishing fluid.

We claim:
 1. A device for extinguishing fires by means of anextinguishing fluid, comprising:a pressure generator for supply of theextinguishing fluid; fire extinguishing nozzle-heads; a supply pipe forconducting the extinguishing fluid from the pressure generator to thefire extinguishing nozzles; each of the fire extinguishing nozzle-headscomprising at least one fire extinguishing nozzle and a fire detectioncontrivance triggered by the presence of heat produced in the event of afire; each of the fire extinguishing nozzle-heads further including afirst shut-off device, a second shut-off device, and at least twoconnecting channels providing communication between the fireextinguishing nozzles and the supply pipe, one of the connectingchannels being closed by the first shut-off device while said fireextinguishing nozzle-head is in a quiescent state and said extinguishingfluid is below a minimum pressure, said first shut-off device openingwhen the minimum pressure is exceeded, and another of the connectingchannels being closed by the second shut-off device while in saidquiescent state, and which is opened in response to triggering of saidfire detection contrivance, opening of either of said connectingchannels in a particular fire extinguishing nozzle-head resulting inissue of the extinguishing fluid from the at least one fireextinguishing nozzle.
 2. The device according to claim 1, wherein thefirst shut-off device is a bursting disk.
 3. A fire extinguishingnozzle-head for a device for extinguishing fires by means of anextinguishing fluid delivered via a supply pipe from a pressuregenerator, comprising:at least one fire extinguishing nozzle; at leasttwo connecting channels providing communication between the fireextinguishing nozzles and the supply pipe; a fire detection contrivancewhich is triggered in the presence of heat generated in the event of afire; and a first shut-off device for closing one of the connectingchannels while said extinguishing fluid is below a minimum pressure,said first shut-off device opening when the minimum pressure isexceeded; and a second shut-off device for normally closing another ofthe connecting channels, said second shut-off device being coupled tothe fire detection contrivance in a manner causing the second shut-offdevice to open in response to triggering of the fire detectioncontrivance.
 4. The fire extinguishing nozzle-head according to claim 3,wherein:the fire detection contrivance is an element destructible by theeffect of heat; and the second shut-off device coupled to the firedetection contrivance includes a movable valve piston supported on theelement and spring biased thereagainst.
 5. The fire extinguishingnozzle-head according to claim 4, wherein the fire detection contrivanceis a glass vial.
 6. The fire extinguishing nozzle-head according toclaim 3, wherein the fire extinguishing nozzles generate anextinguishing mist from the extinguishing fluid.
 7. The fireextinguishing nozzle-head according to claim 3, wherein the firstshut-off device is a bursting disk.